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Journal of the Korea Concrete Institute

J Korea Inst. Struct. Maint. Insp.
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  • Korea Citation Index (KCI)

  1. ์ •ํšŒ์›,ํ•œ๊ตญ๊ฑด์„ค๊ธฐ์ˆ ์—ฐ๊ตฌ์› ๊ตฌ์กฐ์—ฐ๊ตฌ๋ณธ๋ถ€ ์ˆ˜์„์—ฐ๊ตฌ์›
  2. ์ •ํšŒ์›,ใˆœ์ด๋…ธ์˜จ ๋Œ€ํ‘œ์ด์‚ฌ
  3. ์ •ํšŒ์›,ใˆœ์œ ์‹ ์—”์ง€๋‹ˆ์–ด๋ง ์ „๋ฌด
  4. ์ •ํšŒ์›,์„ธ์ข…๋Œ€ํ•™๊ต ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๊ณผ ์กฐ๊ต์ˆ˜, ๊ต์‹ ์ €์ž



IoT ์„ผ์„œ, ์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง, ์žฅ๋ ฅ, ๊ฐ์‡ ๋น„, ์—ฃ์ง€์ปดํ“จํŒ…, ์™„์ „ ์ž๋™ํ™”
IoT system, Cable-monitoring, Tension, Damping ratio, Edge-computing, Full automation

1. ์„œ ๋ก 

์‚ฌ์žฅ๊ต๋Š” ๋Œ€ํ‘œ์ ์ธ ์ผ€์ด๋ธ” ์ง€์ง€ ๊ตฌ์กฐ๋ฌผ ์ค‘ ํ•˜๋‚˜๋กœ ๋ณด๊ฐ•ํ˜•์„ ์ฃผํƒ‘์— ์—ฐ๊ฒฐ๋œ ์‚ฌ์žฅ ์ผ€์ด๋ธ”๋กœ ์ง€์ง€ํ•˜๋Š” ํ˜•์‹์˜ ๊ต๋Ÿ‰์„ ๋งํ•œ๋‹ค. ์‚ฌ์žฅ๊ต๋Š” ์ผ€์ด๋ธ”์˜ ์ธ์žฅ๊ฐ•๋„์™€ ์ฃผํƒ‘ ๋ฐ ๋ณด๊ฐ•ํ˜•์˜ ํœจ, ์••์ถ•๊ฐ•๋„๋ฅผ ํšจ๊ณผ์ ์œผ๋กœ ๊ฒฐํ•ฉ์‹œ์ผœ ๊ตฌ์กฐ์  ํšจ์œจ์„ ๋†’์ผ ์ˆ˜ ์žˆ์–ด์„œ ์žฅ๋Œ€๊ต๋Ÿ‰์— ์ ํ•ฉํ•˜๊ณ , ๋ฏธ๊ด€์ด ๋›ฐ์–ด๋‚˜ ์งง์€ ๊ฑฐ๋ฆฌ์—๋„ ์ข…์ข… ์‚ฌ์šฉ๋˜๊ณ  ์žˆ์–ด, ๊ตญ๋‚ด์—์„œ๋„ ๊ณต์šฉ ์ค‘์ธ ์‚ฌ์žฅ๊ต๊ฐ€ ์ฆ๊ฐ€ํ•˜๊ณ  ์žˆ์œผ๋ฉฐ 2023๋…„ ๊ธฐ์ค€ 78๊ฐœ์†Œ์ด๋‹ค(KICT, 2023). ์‚ฌ์žฅ๊ต ์ผ€์ด๋ธ”์€ ๊ต๋Ÿ‰ ์ „์ฒด์˜ ๊ตฌ์กฐ์•ˆ์ „์„ฑ ๋ฐ ์‚ฌ์šฉ์„ฑ ์ธก๋ฉด์—์„œ ๋งค์šฐ ์ค‘์š”ํ•œ ๊ตฌ์กฐ ๋ถ€์žฌ์ด๋‹ค(Cho et al., 2005). ์‚ฌ์žฅ๊ต๊ฐ€ ์žฅ๋Œ€ํ™”๋ ์ˆ˜๋ก ์ฃผํƒ‘๊ณผ ์ฃผํ˜•์„ ์—ฐ๊ฒฐํ•˜๋Š” ์‚ฌ์žฅ๊ต ์ผ€์ด๋ธ”์€ ํ’ํ•˜์ค‘ ๋ฐ ์ฐจ๋Ÿ‰ํ•˜์ค‘์— ์˜ํ•œ ์ง„๋™์— ์ทจ์•ฝํ•ด์ง„๋‹ค. ์‚ฌ์žฅ๊ต์— ์„ค์น˜๋˜๋Š” ์ผ€์ด๋ธ” ๋Œํผ๋Š” ์ผ€์ด๋ธ”์˜ ๊ฐ์‡ ๋น„๋ฅผ ์ฆ๊ฐ€์‹œ์ผœ ์ผ€์ด๋ธ” ๋ฐ ๊ต๋Ÿ‰์— ํ”ผ๋กœ ๋ฐ ์•ˆ์ •์„ฑ ๋ฌธ์ œ๋ฅผ ์œ ๋ฐœํ•˜๋Š” ์ง„๋™์„ ์ €๊ฐ์‹œํ‚ค๋Š” ์—ญํ• ์„ ํ•œ๋‹ค. ์ฆ‰, ์ผ€์ด๋ธ” ๋ฐ ์ผ€์ด๋ธ” ๋Œํผ์˜ ์„ฑ๋Šฅ์„ ํ™•๋ณดํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์ผ€์ด๋ธ”์˜ ์žฅ๋ ฅ๊ณผ ๊ฐ์‡ ๋น„๋ฅผ ๋ชจ๋‹ˆํ„ฐ๋งํ•˜๋Š” ๊ฒƒ์€ ๋งค์šฐ ์ค‘์š”ํ•œ ๋ฌธ์ œ์ด๋‹ค.

์ผ€์ด๋ธ” ์žฅ๋ ฅ์„ ์ธก์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์€ ์žฅ๋ ฅ ์ธก์ •์žฅ๋น„๋ฅผ ์ด์šฉํ•˜๋Š” ์ง์ ‘๋ฒ•๊ณผ ๋™์  ๋ฐ์ดํ„ฐ๋ฅผ ์ด์šฉํ•˜๋Š” ๊ฐ„์ ‘๋ฒ•์ด ์žˆ๋‹ค(Cho et al., 2005).์ง์ ‘๋ฒ•์€ ์ผ€์ด๋ธ”์— ๋กœ๋“œ์…€๊ณผ ๋ณ€์œ„๊ณ„, ์œ ์••์žญ์„ ์„ค์น˜ํ•œ ํ›„ ๋กœ๋“œ์…€์— ๊ฑธ๋ฆฌ๋Š” ํž˜๊ณผ ๋ณ€์œ„๊ณ„๋กœ ์ธก์ •ํ•œ ๋ณ€์œ„์™€์˜ ๊ด€๊ณ„๋ฅผ ์ด์šฉํ•˜์—ฌ ์ผ€์ด๋ธ”์˜ ์žฅ๋ ฅ์„ ์‚ฐ์ •ํ•˜๋Š” ๋ฐฉ์‹์ด๋‹ค. ๊ณผ์ •์ด ๋‹จ์ˆœํ•˜๊ณ  ๊ฒฐ๊ณผ๊ฐ’์ด ์ •ํ™•ํ•œ ๋ฐ˜๋ฉด, ๊ณ ๊ฐ€์ด๊ณ , ์œ ์ง€๊ด€๋ฆฌ์— ์–ด๋ ค์›€์ด ์žˆ์œผ๋ฉฐ, ๊ณต์šฉ ์ค‘์ธ ๊ต๋Ÿ‰์— ์ ์šฉํ•˜๊ธฐ ์–ด๋ ต๋‹ค. ์‚ฌ์žฅ๊ต ์ผ€์ด๋ธ” ๊ธด์žฅ๋ ฅ ๋ชจ๋‹ˆํ„ฐ๋ง์„ ์œ„ํ•˜์—ฌ Park et al. (2020)์€ FBG ๊ด‘์„ฌ์œ  ์„ผ์„œ๊ฐ€ ๋‚ด์žฅ๋˜์–ด ์žˆ๋Š” ์Šค๋งˆํŠธ ๊ฐ•์—ฐ์„ ์„ ์ด์šฉํ•˜์—ฌ ๊ธด์žฅ๋ ฅ์„ ์ง์ ‘ ์ธก์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์„ ์ œ์•ˆํ•˜์˜€๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ด ๋ฐฉ๋ฒ•์€ ๊ธฐ์กด ์ผ€์ด๋ธ”์„ ์Šค๋งˆํŠธ ๊ฐ•์—ฐ์„ ์œผ๋กœ ๊ต์ฒดํ•˜๋Š” ์ž‘์—…์ด ํ•„์š”ํ•˜๋ฉฐ, ์šด์šฉ ์ค‘ ์„ผ์„œ์— ์†์ƒ์ด ๋ฐœ์ƒํ•˜์˜€์„ ๊ฒฝ์šฐ ๋ณด์ˆ˜์— ์–ด๋ ค์›€์ด ์žˆ๋‹ค. ๋”ฐ๋ผ์„œ ๋™์  ๊ฐ€์†๋„ ๋ฐ์ดํ„ฐ๋ฅผ ์ด์šฉํ•˜์—ฌ ๊ฐ„์ ‘์ ์œผ๋กœ ์žฅ๋ ฅ์„ ์ถ”์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์ด ์ผ๋ฐ˜์ ์œผ๋กœ ํ˜„์žฅ์—์„œ ์‚ฌ์šฉ๋œ๋‹ค. ์ง„๋™๋ฒ•์€ ์ผ€์ด๋ธ” ์žฅ๋ ฅ์ด ๋ณ€ํ™”ํ•˜๋ฉด์„œ ์ผ€์ด๋ธ” ๋™์  ํŠน์„ฑ์ด ๋ณ€ํ™”ํ•˜๋Š” ๊ด€๊ณ„์— ๊ธฐ๋ฐ˜์„ ๋‘” ๋ฐฉ๋ฒ•์œผ๋กœ, ์—ฌ๋Ÿฌ ์—ฐ๊ตฌ์ž์— ์˜ํ•˜์—ฌ ์ œ์•ˆ๋˜์—ˆ๋‹ค(Juan 1994, Russel 1998). ๊ตญํ† ์•ˆ์ „๊ด€๋ฆฌ์› ํŠน์ˆ˜์‹œ์„ค๊ด€๋ฆฌ์‹ค์—์„œ ๊ด€๋ฆฌ ์ค‘์ธ ์‚ฌ์žฅ๊ต์—๋Š” ๊ฐ€์†๋„ ๋ฐ์ดํ„ฐ๋ฅผ ํ™œ์šฉํ•œ ์ง„๋™๋ฒ•์„ ๊ธฐ๋ฐ˜์œผ๋กœ ์žฅ๋ ฅ์„ ์ถ”์ •์„ ์œ„ํ•ด ์„ค์น˜๋œ ์ผ€์ด๋ธ” ๊ฐ€์†๋„๊ณ„๋Š” 2022๋…„ ๊ธฐ์ค€์œผ๋กœ 206๊ฐœ์ด๋‹ค(KALIS, 2022).

์ง„๋™๋ฒ• ๊ธฐ๋ฐ˜ ์ผ€์ด๋ธ” ์žฅ๋ ฅ ๋ฐ ๊ฐ์‡ ๋น„ ๊ฐ’์˜ ์ถ”์ •์€ Fig. 1์˜ ์ˆœ์„œ๋กœ ์ง„ํ–‰๋œ๋‹ค. ์šฐ์„ , ์ผ€์ด๋ธ”๊ณผ ์ผ์ฒด ๊ฑฐ๋™์„ ํ•˜๋„๋ก ๊ฐ€์†๋„๊ณ„๋ฅผ ์„ค์น˜ํ•œ ๋‹ค์Œ, ์‹œ๊ฐ„์˜์—ญ ์ง„๋™ ์‘๋‹ต์„ ์‹ค์‹œ๊ฐ„์œผ๋กœ ๊ณ„์ธกํ•œ๋‹ค. ์ดํ›„ ๊ณ„์ธก๋œ ์ง„๋™ ์‘๋‹ต์„ ์ฃผํŒŒ์ˆ˜ ์˜์—ญ์œผ๋กœ ๋ณ€ํ™˜ํ•˜์—ฌ ํŒŒ์›Œ ์ŠคํŽ™ํŠธ๋Ÿผ ๋ฐ€๋„(power spectral density, PSD)๋ฅผ ๊ณ„์‚ฐํ•˜๊ณ , PSD ์‹ ํ˜ธ๋กœ๋ถ€ํ„ฐ ์ฒจ๋‘๊ฐ’(peak values)์„ ์ถ”์ถœํ•œ๋‹ค. ์ฒจ๋‘๊ฐ’๊ณผ ์žฅ๋ ฅ, ๊ฐ์‡ ๋น„ ๊ฐ„์˜ ์ƒ๊ด€๊ด€๊ณ„์‹์„ ํ†ตํ•˜์—ฌ ์žฅ๋ ฅ ๋ฐ ๊ฐ์‡ ๋น„๋ฅผ ์—ญ์œผ๋กœ ์ถ”์ •ํ•œ๋‹ค. ๋งค๋ฒˆ ์ƒˆ๋กญ๊ฒŒ ๊ณ„์ธก๋œ ์‘๋‹ต์— ๋Œ€ํ•˜์—ฌ ์œ„์˜ ๊ณผ์ •์„ ๋ฐ˜๋ณต์ ์œผ๋กœ ์ˆ˜ํ–‰ํ•˜์—ฌ ์žฅ๋ ฅ ๋ฐ ๊ฐ์‡ ๋น„๋ฅผ ๋ชจ๋‹ˆํ„ฐ๋งํ•œ๋‹ค. ์ด ๊ณผ์ •์—์„œ ์‚ฌ๋žŒ์˜ ๊ฐœ์ž…์ด ํ•„์š”ํ•˜๊ณ  ๊ฒฐ๊ณผ์— ๊ฐ€์žฅ ํฐ ์˜ํ–ฅ์„ ๋ฏธ์น˜๋Š” ์ž‘์—…์€ ์ฒจ๋‘๊ฐ’์„ ์ถ”์ถœํ•˜๋Š” ๊ฒƒ์ด๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ PSD ์‹ ํ˜ธ์—์„œ์˜ ์ฒจ๋‘๊ฐ’์€ ํ’ํ•˜์ค‘, ์ฐจ๋Ÿ‰ํ•˜์ค‘ ๋“ฑ ์ผ€์ด๋ธ”์— ์˜ํ–ฅ์„ ๋ฏธ์น˜๋Š” ์™ธ๋ถ€ ํ•˜์ค‘๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ์„ผ์„œ ์ƒํƒœ, ํ†ต์‹  ํ’ˆ์งˆ ๋“ฑ์— ๋Œ€ํ•œ ์˜ํ–ฅ์ด ํ•จ๊ป˜ ๋ฐ˜์˜๋˜๊ธฐ ๋•Œ๋ฌธ์— ์‹œ๊ฐ„์ด ๊ฒฝ๊ณผํ•จ์— ๋”ฐ๋ผ ํŽธํ–ฅ ๋“ฑ์œผ๋กœ ์ตœ์ดˆ ์„ค์ •๊ฐ’์ด ๋ณ€๊ฒฝ๋  ์ˆ˜ ์žˆ์œผ๋ฉฐ ์ง€์†์ ์ธ ์ธ๋ ฅ ๊ฐœ์ž…์ด ํ•„์š”ํ•˜๋‹ค. ๋”ฐ๋ผ์„œ, ์ฒจ๋‘๊ฐ’์„ ์ถ”์ถœํ•˜๋Š” ๋ฐ ์žˆ์–ด์„œ ์‹ ํ˜ธ ๋ณด์ •, ๋ณ€์ˆ˜ ์„ค์ • ๋“ฑ ์ธ๋ ฅ ๊ฐœ์ž…์„ ์ตœ์†Œํ™”ํ•˜๋Š” ๊ฒƒ์€, ์ถ”์ • ๊ฒฐ๊ณผ์˜ ๊ฐ๊ด€์„ฑ ๋ฐ ์‹ ๋ขฐ์„ฑ์„ ํ™•๋ณดํ•˜๋Š” ๋ฐ ์žˆ์–ด ๋งค์šฐ ์ค‘์š”ํ•˜๋ฉฐ, ๋…ธ๋™์ง‘์•ฝ์ ์ธ ์‹ ํ˜ธ์ฒ˜๋ฆฌ ์ž‘์—…์„ ๋ฌด์ธ ์ž๋™ํ™”ํ•˜๊ธฐ ์œ„ํ•œ ๊ธฐ๋ฐ˜์ด ๋œ๋‹ค.

Fig. 1 Tension and damping ratio estimation based on the indirect method with vibration data
../../Resources/ksm/jksmi.2024.28.3.66/fig1.png

ํŠน์ˆ˜์‹œ์„ค๊ด€๋ฆฌ์‹ค์—์„œ ๊ด€๋ฆฌ ์ค‘์ธ ์ผ€์ด๋ธ” ๊ต๋Ÿ‰์˜ ์ผ€์ด๋ธ” ์žฅ๋ ฅ๊ณ„ ๋Œ€๋‹ค์ˆ˜๋Š” ์œ ์„  ๊ณ„์ธก์‹œ์Šคํ…œ์ด๋‹ค. ์œ ์„  ๊ณ„์ธก ์‹œ์Šคํ…œ์€ ์„ผ์„œ, ํ†ต์‹ , ์ „๋ ฅ ์ผ€์ด๋ธ”์˜ ์„ค์น˜๊ฐ€ ํ•„์š”ํ•˜์—ฌ ์ˆ˜๋Ÿ‰ ๋ฐ ์œ„์น˜ ์„ ์ •์— ์ œ์•ฝ์ด ์žˆ์œผ๋ฉฐ, ์ผ€์ด๋ธ” ์„ค์น˜ ๋น„์šฉ์ด ์ƒ๋‹นํ•˜๋‹ค. ์ด๋ฅผ ์œ„ํ•˜์—ฌ ๋ฌด์„  ๊ณ„์ธก์‹œ์Šคํ…œ์ด 2000๋…„๋Œ€๋ถ€ํ„ฐ ๊ฐœ๋ฐœ๋˜๊ธฐ ์‹œ์ž‘ํ•˜์˜€์œผ๋ฉฐ(Hou and Wu, 2019; Peng et al. 2023), ์ตœ๊ทผ IoT ๊ธฐ์ˆ ์˜ ๊ธ‰๊ฒฉํ•œ ๋ฐœ์ „๊ณผ ํ•จ๊ป˜ IoT ์„ผ์„œ ์ƒ๋‹น์ˆ˜๊ฐ€ ๊ต๋Ÿ‰์— ์„ค์น˜๋˜๊ณ  ์žˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ƒ๋‹น์ˆ˜๊ฐ€ ์›์‹œ(raw) ์‹ ํ˜ธ ๊ณ„์ธก ๋ฐ ๋ฌด์„  ๋ฐ์ดํ„ฐ ์†ก์ˆ˜์‹ ์„ ์œ„ํ•œ ๊ธฐ๋ณธ ๊ธฐ๋Šฅ, ์„ผ์„œ ์ƒํƒœ ํ™•์ธ ๊ธฐ๋Šฅ, ์›์‹œ ์‹ ํ˜ธ์˜ ํ†ต๊ณ„์ฒ˜๋ฆฌ ๊ธฐ๋Šฅ๋งŒ์„ ๊ฐ–์ถ”๊ณ  ์žˆ๋‹ค. ์ง„๋™๋ฒ• ๊ธฐ๋ฐ˜ ์ผ€์ด๋ธ” ์žฅ๋ ฅ ๋ฐ ๊ฐ์‡ ๋น„ ์ถ”์ •์„ ์œ„ํ•˜์—ฌ ์ดˆ๋‹น 100ํšŒ ์ด์ƒ ๊ณ„์ธก ์ฃผ๊ธฐ๋กœ 10๋ถ„ ์ด์ƒ ์›์‹œ ์ง„๋™ ๋ฐ์ดํ„ฐ๋ฅผ ์ˆ˜์ง‘ํ•˜๋Š”๋ฐ, ์ˆ˜์ง‘๋œ ๋ฐ์ดํ„ฐ๋Š” ๊ธฐ๋ณธ์ ์ธ ์ฒ˜๋ฆฌ๋งŒ ๊ฑฐ์ณ ์„œ๋ฒ„๋กœ ์ „์†ก๋˜๊ณ , ์„œ๋ฒ„์—์„œ ์ „์†ก๋ฐ›์€ ๋ฐ์ดํ„ฐ์— ๋Œ€ํ•œ ๋ถ„์„์„ ์ˆ˜ํ–‰ํ•˜์—ฌ ์žฅ๋ ฅ๊ณผ ๊ฐ์‡ ๋น„๋ฅผ ๊ณ„์‚ฐํ•˜๋Š” ๋ฐฉ์‹์ด๋‹ค. ์ตœ๊ทผ Edge Computing ๊ธฐ์ˆ ์„ ํ†ตํ•ด ์ค‘์•™ ํด๋ผ์šฐ๋“œ ์„œ๋ฒ„๊ฐ€ ์•„๋‹ˆ๋ผ IoT ์„ผ์„œ ์ž์ฒด์—์„œ ๋ฐ์ดํ„ฐ๋ฅผ ์ฒ˜๋ฆฌํ•˜๋Š” ๊ธฐ์ˆ ์ด ๊ฐœ๋ฐœ๋˜๊ณ  ์žˆ์œผ๋ฉฐ, ์ฃผ๋กœ ๋ฐ์ดํ„ฐ์˜ ์–‘์ด ๋งค์šฐ ๋งŽ๊ณ  ์‹ค์‹œ๊ฐ„์ ์ธ ์ฒ˜๋ฆฌ๊ฐ€ ํ•„์š”ํ•œ ์ž์œจ์ฃผํ–‰์ž๋™์ฐจ, ์Šค๋งˆํŠธ ๊ณต์žฅ, ์‚ฌ๋ฌผ์ธํ„ฐ๋„ท(IoT) ๋“ฑ์—์„œ ๋Œ€๊ฑฐ ํ™œ์šฉ๋˜๊ณ  ์žˆ๋‹ค. ์ด๋Ÿฌํ•œ Edge Computing ๊ธฐ์ˆ ์„ ํ™œ์šฉํ•˜์—ฌ ์ผ€์ด๋ธ”์˜ ์žฅ๋ ฅ ๋ฐ ๊ฐ์‡ ๋น„ ์ถ”์ • ๊ฒฐ๊ณผ๋งŒ์„ ์„œ๋ฒ„๋กœ ์ „์†กํ•  ์ˆ˜ ์žˆ๋‹ค๋ฉด, ๋ฐ์ด์„œ ์†ก์ˆ˜์‹  ํฌ๊ธฐ๋ฅผ ๋Œ€ํญ ๊ฐ์†Œ์‹œํ‚ฌ ์ˆ˜ ์žˆ์œผ๋ฉฐ, ์ด๋Š” ์ „๋ ฅ๋Ÿ‰ ๋ฐ ํ†ต์‹ ๋Ÿ‰์˜ ๊ฐ์†Œ๋กœ ์ด์–ด์ ธ ๊ธฐ์กด ์›์‹œ ๋ฐ์ดํ„ฐ ์†ก์‹  ์‹œ์Šคํ…œ๋ณด๋‹ค ํšจ์œจ์ ์ธ ์šด์˜ ๋ฐ ๊ด€๋ฆฌ๊ฐ€ ๊ฐ€๋Šฅํ•˜๋‹ค(Sim and Spencer 2010; Jeong et al., 2019; Kim et al., 2019).

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ธ๋ ฅ์˜ ๊ฐœ์ž…์„ ์ตœ์†Œํ™”ํ•˜์—ฌ ์™„์ „ ์ž๋™ํ™”๋œ ์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง ์‹œ์Šคํ…œ์„ ๊ตฌ์ถ•ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ, ๊ฐ€์†๋„ ์‹ ํ˜ธ๋กœ๋ถ€ํ„ฐ ์ฒจ๋‘๋ฅผ ์ถ”์ถœํ•˜๊ธฐ ์œ„ํ•œ ์ „์ฒด ๊ณผ์ •์„ ์ž๋™ํ™”ํ•œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ IoT ์„ผ์„œ์— ํƒ‘์žฌํ•˜๊ณ  ์‹œ์Šคํ…œ์„ ์ตœ์ ํ™”ํ•œ ๋‹ค์Œ, ํ˜„์žฌ ์œ ์„  ๊ณ„์ธก์‹œ์Šคํ…œ์ด ์„ค์น˜๋˜์–ด ์žฅ๋ ฅ์„ ๊ด€๋ฆฌ ์ค‘์ธ ๊ตญ๋‚ด ์‚ฌ์žฅ๊ต์— ์„ค์น˜ํ•˜์—ฌ ์„ผ์„œ ๋ฐ ์•Œ๊ณ ๋ฆฌ์ฆ˜์˜ ์ •ํ™•์„ฑ๊ณผ ํ˜„์žฅ ์šด์šฉ์„ฑ์„ ๊ฒ€์ฆํ•˜๊ณ ์ž ํ•œ๋‹ค.

2. ์ฒจ๋‘ ์ž๋™ ํƒ์ง€ ์•Œ๊ณ ๋ฆฌ์ฆ˜

์ผ์ • ๊ธฐ๊ฐ„ ๊ณ„์ธก๋œ ๊ฐ€์†๋„ ์‹ ํ˜ธ์— ๋Œ€ํ•˜์—ฌ ์ฃผํŒŒ์ˆ˜ ์˜์—ญ์—์„œ์˜ ์ฒจ๋‘๊ฐ’์„ ์ž๋™์œผ๋กœ ์ถ”์ถœํ•  ์ˆ˜ ์žˆ๋Š” ์•Œ๊ณ ๋ฆฌ์ฆ˜์€ ์ผ€์ด๋ธ”์˜ ์ง„๋™ ํŠน์ง•์— ๊ธฐ๋ฐ˜ํ•˜์—ฌ ๊ฐœ๋ฐœ๋˜์—ˆ๋‹ค. ์ผ€์ด๋ธ”์—์„œ ์ธก์ •ํ•œ ์ง„๋™ ์‹ ํ˜ธ๋ฅผ ์ฃผํŒŒ์ˆ˜ ์˜์—ญ์œผ๋กœ ๋ณ€ํ™˜ํ•˜๋ฉด ๋‹ค์Œ์˜ ๋‘ ๊ฐ€์ง€ ํŠน์ง•์ด ๋‚˜ํƒ€๋‚œ๋‹ค: (1) ์ผ€์ด๋ธ”์˜ ์ฒจ๋‘๊ฐ’์€ ์ผ€์ด๋ธ”์˜ ๊ณ ์œ ์ง„๋™์ˆ˜์™€ ๊ด€๋ จ์ด ์žˆ์œผ๋ฏ€๋กœ ์ผ์ • ๊ฐ„๊ฒฉ์„ ๊ฐ€์ง€๊ณ  ๋‚˜ํƒ€๋‚œ๋‹ค. ์ฒจ๋‘๊ฐ’ ๊ฐ„์˜ ๊ฐ„๊ฒฉ์€ ์ผ€์ด๋ธ” ๊ณ ์œ  ๋ฌผ๋ฆฌ์  ํŠน์ง•์œผ๋กœ ์ผ€์ด๋ธ”์˜ ์ œ์› ๋ฐ ํ˜•์ƒ์— ๋”ฐ๋ผ ๋‹ฌ๋ผ์ง„๋‹ค; (2) ์ฒจ๋‘๊ฐ’์€ ์ฃผ๋ณ€๊ฐ’์— ๋น„ํ•˜์—ฌ ํฐ ๊ฐ’์„ ๊ฐ€์ง€๊ณ  ์žˆ์–ด ์ด์ƒ์น˜์™€ ์œ ์‚ฌํ•˜๋‹ค. ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ์ด์™€ ๊ฐ™์€ ๋‘ ๊ฐ€์ง€ ํŠน์ง•์„ ํŒ๋ณ„ํ•˜์—ฌ ์ฒจ๋‘๊ฐ’์„ ์ž๋™์œผ๋กœ ์ถ”์ถœํ•  ์ˆ˜ ์žˆ๋Š” ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค(Jin et al, 2021).

Fig. 2 Fully-automated peak detection algorithm(Jin et al., 2021)
../../Resources/ksm/jksmi.2024.28.3.66/fig2.png

์ƒ์ฒด์‹ ํ˜ธ ์ฒ˜๋ฆฌ๋ถ„์•ผ์—์„œ๋Š” ์ฒจ๋‘๊ฐ’์ด ์ฃผ๊ธฐ์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ํŠน์ง•์„ ์ด์šฉํ•˜์—ฌ Automatic multiscale-based peak detection (AMPD) ๊ธฐ๋ฒ•์„ ์ œ์•ˆํ•˜์˜€๋‹ค(Scholkmanm et al, 2012). AMPD ๊ธฐ๋ฒ•์€ ์žก์Œ์ด ํฌํ•จ๋œ ์‹ ํ˜ธ์—์„œ๋„ ์ฃผ๊ธฐ์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ์ฒจ๋‘๊ฐ’ ์ถ”์ •์ด ๊ฐ€๋Šฅํ•˜๋ฉฐ, ์ดˆ๊ธฐ ์„ค์ •์ด ํ•„์š” ์—†์–ด ์ž๋™ํ™”๊ฐ€ ๊ฐ€๋Šฅํ•˜๋‹ค๋Š” ์žฅ์ ์ด ์žˆ๋‹ค. Jin et al. (2021)์€ ์ƒ์ฒด์‹ ํ˜ธ๋ฅผ ๊ธฐ๋ฐ˜์œผ๋กœ ๊ฐœ๋ฐœ๋œ AMPD ๊ธฐ๋ฒ•์„ ์ผ€์ด๋ธ”์˜ ์‹ ํ˜ธ ํŠน์„ฑ์— ๋งž์ถฐ ๊ฐœ์„ ํ•˜์˜€๋‹ค. ํ•œํŽธ, ์ฃผ๋ณ€๊ฐ’๊ณผ ๋น„๊ตํ•˜์—ฌ ์ด๋ฅผ ์ดˆ๊ณผํ•˜๋Š” ์ด์ƒ์น˜๋ฅผ ํƒ์ง€ํ•˜๋Š” ๋ฐ์— ์žˆ์–ด์„œ ์žก์Œ์ด ํฌํ•จ๋œ ์‹ ํ˜ธ์—์„œ๋„ ์•ˆ์ •์ ์œผ๋กœ ์ฒจ๋‘๋ฅผ ํƒ์ง€ํ•  ์ˆ˜ ์žˆ๋„๋ก ์ค‘์•™๊ฐ’ ์ ˆ๋Œ€ ํŽธ์ฐจ(Median absolute deviations, MAD) ๋ฐฉ๋ฒ•์„ ์‚ฌ์šฉํ•˜์—ฌ ์ž„๊ณ„์น˜๋ฅผ ์ž๋™์œผ๋กœ ์„ค์ •ํ•˜๋„๋ก ํ•˜์˜€๋‹ค(Rousseeuw et al., 1993). ์ด์™€ ๊ฐ™์€ ๋‘ ๊ฐ€์ง€์˜ ๋ฌผ๋ฆฌ์  ํŠน์ง•์œผ๋กœ๋ถ€ํ„ฐ ํƒ์ง€๋œ ์ฒจ๋‘ ์ค‘ ๊ณตํ†ต์œผ๋กœ ๋‚˜ํƒ€๋‚˜๋Š” ์ฒจ๋‘์— ๋Œ€ํ•˜์—ฌ ์žฅ๋ ฅ์„ ์ถ”์ •ํ•˜๋„๋ก ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ๊ฐœ๋ฐœํ•˜์˜€์œผ๋ฉฐ, Jin et al. (2021)์€ ์•Œ๊ณ ๋ฆฌ์ฆ˜์˜ ์ •ํ™•์„ฑ์„ ๊ธฐ์กด ๊ธฐ๋ฒ• ๋ฐ ๋”ฅ๋Ÿฌ๋‹ ๊ฐ์ฒดํƒ์ง€ ์•Œ๊ณ ๋ฆฌ์ฆ˜๊ณผ ๋น„๊ตยท๊ฒ€์ฆํ•˜์˜€๋‹ค.

๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ํ•ด๋‹น ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ IoT ์„ผ์„œ์— ํƒ‘์žฌํ•˜๊ธฐ ์œ„ํ•˜์—ฌ, ์‚ฌ์šฉ์ž๊ฐ€ ์‚ฌ์ „์— ์„ค์ •ํ•ด์•ผ ํ•˜๋Š” ์„ค์ • ๋ณ€์ˆ˜(hyper-parameters)๊ฐ€ ํ•„์š” ์—†์œผ๋ฉฐ, ์‚ฌ์ „ํ•™์Šต, ์‹คํ–‰์‹œ๊ฐ„ ๋“ฑ ์—ฐ์‚ฐ์˜ ๋ณต์žก์„ฑ ๋ฐ ์—ฐ์‚ฐ ์‹œ ์š”๊ตฌ๋˜๋Š” ๋น„์šฉ์„ ๋‚ฎ์ถค์œผ๋กœ์จ, ์‚ฌ์šฉ์ž์˜ ๊ฐœ์ž…์ด ์ „ํ˜€ ์—†์ด ์ฒจ๋‘ ์ถ”์ • ์™„์ „ ์ž๋™ํ™”๊ฐ€ ๊ฐ€๋Šฅํ•˜๋‹ค. ์ด๋Ÿฌํ•œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์˜ ํŠน์ง•์„ ๊ธฐ๋ฐ˜์œผ๋กœ ์ €์ „๋ ฅ์œผ๋กœ ์„ผ์„œ ์ž์ฒด์ ์ธ ์‹ค์‹œ๊ฐ„ ๋ฐ์ดํ„ฐ ์ฒ˜๋ฆฌ๊ฐ€ ๊ฐ€๋Šฅํ•˜๋„๋ก ํ•˜์˜€๋‹ค.

3. ๊ต๋Ÿ‰ ์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง ์ž๋™ํ™” ์‹œ์Šคํ…œ ์ œ์ž‘

์ผ€์ด๋ธ” ์›์‹œ ๋ฐ์ดํ„ฐ์—์„œ ์ฒจ๋‘๋ฅผ ์ถ”์ถœํ•˜๊ธฐ ์œ„ํ•œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์ด ์›ํ™œํ•˜๊ฒŒ ๊ตฌ๋™๋  ์ˆ˜ ์žˆ๋„๋ก IoT ์„ผ์„œ๋ฅผ ๊ฐœ๋ฐœํ•˜์˜€๋‹ค. ๊ฐœ๋ฐœ๋œ ์„ผ์„œ๋Š” (1) ์ผ€์ด๋ธ” ๊ฐ€์†๋„ ์‹ ํ˜ธ์˜ ๊ณ„์ธก, (2) ํƒ‘์žฌ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ํ†ตํ•ด ์ฒจ๋‘๊ฐ’ ์ถ”์ถœ, (3) ์žฅ๋ ฅ ๋ฐ ๊ฐ์‡ ๋น„ ๊ณ„์‚ฐ, (4) ์ด์ƒ ์‹ ํ˜ธ ํƒ์ง€ ๋ฐ ๋ถ„๋ฅ˜, (5) ๊ณ„์ธก ์„ผ์„œ ์ƒํƒœ ํ™•์ธ์˜ 5๊ฐ€์ง€ ๊ธฐ๋Šฅ์„ ์ˆ˜ํ–‰ํ•  ์ˆ˜ ์žˆ๋„๋ก ์„ค๊ณ„ยท์ œ์ž‘๋˜์—ˆ๋‹ค. ๊ฐ€์†๋„ ๋ฐ์ดํ„ฐ์˜ ์‹ค์‹œ๊ฐ„ ์ˆ˜์ง‘์„ ์œ„ํ•ด RTOS(Real-Time Operating System)์ธ Zephyr๊ฐ€ ํฌํŒ…๋œ on- board 32bit MCU์™€ ๊ณ ๋„์˜ ์—ฐ์‚ฐ ๋ฐ ๊ณ ์† ๋„คํŠธ์›Œํฌ ์ฒ˜๋ฆฌ๋ฅผ ์œ„ํ•œ ์ฟผ๋“œ์ฝ”์–ด 64bit CPU์— Linux๋ฅผ ํฌํŒ…ํ•œ ๋“€์–ผ ํ”„๋กœ์„ธ์„œ ์‹œ์Šคํ…œ์„ ํƒ‘์žฌํ•˜์˜€์œผ๋ฉฐ, ์‹ค์‹œ๊ฐ„ยท์ €์ „๋ ฅ ๊ณ„์ธก ๋ฐ ๊ณ ๊ธ‰ ์•Œ๊ณ ๋ฆฌ์ฆ˜ ์—ฐ์‚ฐ์„ ์œ ์—ฐํ•˜๊ฒŒ ์ง€์›ํ•  ์ˆ˜ ์žˆ๋‹ค. Fig. 3์€ ๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ์˜ ๋ธ”๋ก ๋‹ค์ด์–ด๊ทธ๋žจ์„, Table 1์€ ์ฃผ์š” ์„ฑ๋Šฅ์„ ๋ณด์—ฌ์ค€๋‹ค.

Fig. 3 Block diagram of the proposed IoT sensor
../../Resources/ksm/jksmi.2024.28.3.66/fig3.png

๊ฐ€์†๋„ ์„ผ์„œ๋Š” 100 Hz ์ƒ˜ํ”Œ๋ง์œผ๋กœ ์›์‹œ ๋ฐ์ดํ„ฐ๋ฅผ ์ƒ์„ฑํ•œ๋‹ค. ์ดํ›„ ์›์‹œ ๋ฐ์ดํ„ฐ๋Š” 10๋ถ„ ๋‹จ์œ„๋กœ ์ €์žฅ๋˜๋ฉฐ, 10๋ถ„๊ฐ„ ์ธก์ •๋œ ๋ฐ์ดํ„ฐ๋ฅผ ๊ธฐ๋ฐ˜์œผ๋กœ ์ฒจ๋‘๊ฐ’ ์ถ”์ถœ์„ ์œ„ํ•œ ์—ฐ์‚ฐ์ด ์ˆ˜ํ–‰๋œ๋‹ค. ๋™์ผํ•œ ๊ตฌ์กฐ์ฒด์— ๋Œ€ํ•˜์—ฌ ๊ฐœ๋ฐœ๋œ ์„ผ์„œ์™€ ๊ธฐ์กด ๊ฐ€์†๋„๊ณ„ ์„ผ์„œ์˜ ์„ฑ๋Šฅ์„ ๋น„๊ตํ•œ ๊ฒฐ๊ณผ, ์‹œ๊ฐ„ ์˜์—ญ์—์„œ ๋‘ ์‹ ํ˜ธ์˜ ์ƒ๊ด€์„ฑ์€ 0.93, ์ฃผํŒŒ์ˆ˜ ์˜์—ญ์—์„œ ์ถ”์ถœ๋œ ์ฒจ๋‘๊ฐ’์€ 3.613 Hz๋กœ ๋™์ผํ•˜์˜€๋‹ค(Fig. 4). ์ด๋•Œ Z์ถ• ๊ฐ€์†๋„ ๋ฐ์ดํ„ฐ๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ์„ผ์„œ์— ํƒ‘์žฌ๋œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์œผ๋กœ๋ถ€ํ„ฐ ์ฒจ๋‘๊ฐ’์„ ์ถ”์ถœํ•˜๋Š” ๋ฐ์— ์†Œ์š”๋˜๋Š” ์‹œ๊ฐ„์€ Fig. 5์—์„œ ๋ณด๋“ฏ์ด ์•ฝ 0.7์ดˆ์˜€๋‹ค.

Fig. 4 Comparison of signals in the frequency domain
../../Resources/ksm/jksmi.2024.28.3.66/fig4.png
Fig. 5 Elapsed time from an embedded algorithm
../../Resources/ksm/jksmi.2024.28.3.66/fig5.png
Table 1 Summary of the proposed IoT sensor

General

Sensor Input Channel

3-axis Acceleration, 6-ch Analog Input (single ended/differential)

Internal Sensor

1-ch Internal temperature, 1-ch Internal humidity

Data Storage

External 256GB SD Memory

Power Consumption

300mA (sensing), < 1mA (sleep)

Analog Signal Acquisition

Effective number of bits (ENOB)

24 bits

Maximum sampling frequency

100Hz

Input voltage range

0-3.3 V

Accuracy

0.04%

Acceleration Sensing

Acceleration range (selectable)

ยฑ2 g

Noise floor, Z axis

0.1 mg

Noise floor, X and Y axes

0.1 mg

LTE Module

Data rate

50Mbps

Maximum transmission distance

Unlimited

Operating Parameters

Temperature range (default enclosure)

-20 to +60 C

Temperature range (custom enclosure)

-20 to +85 C

Internal power source

Internal 3.7 V DC, 19,600 mAh, rechargeable Li polymer battery

External power source

4.5~16 V DC

Physical Specifications

Dimensions

190.9 ร— 99.5 ร— 60 mm

Weight

1,180 g

Environmental rating

IP65

Material

Aluminum

์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง ์ค‘ ์„ผ์„œ์˜ ์œ ์ง€๊ด€๋ฆฌ๋ฅผ ์œ„ํ•˜์—ฌ ์„ผ์„œ ๋‚ด๋ถ€์— ์˜จ๋„์„ผ์„œ, ์Šต๋„์„ผ์„œ๋ฅผ ์žฅ์ฐฉํ•˜์—ฌ ๋ชจ๋‹ˆํ„ฐ๋ง ์ค‘ ์˜จยท์Šต๋„๊ฐ’, ๋‚ด๋ถ€ ๋ฐฐํ„ฐ๋ฆฌ ์ „์••, ์™ธ๋ถ€ ํƒœ์–‘๊ด‘ ์ „์••, ํ†ต์‹  ์„ฑ๋Šฅ ๋ณ€์ˆ˜๋ฅผ ์ถ”์ถœํ•˜์—ฌ ๋งค ์‹œ๊ฐ„๋งˆ๋‹ค ์„œ๋ฒ„๋กœ ์ „์†กํ•จ์œผ๋กœ์จ, ์„ผ์„œ ์ƒํƒœ์— ๋Œ€ํ•œ ๋ฐ์ดํ„ฐ๋ฅผ ์ถ•์ ํ•˜์—ฌ ๊ด€๋ฆฌํ•˜๋„๋ก ํ•˜์˜€๋‹ค. ํ•œํŽธ, ์™ธ๋ถ€ ํ™˜๊ฒฝ์— ์žฅ๊ธฐ๊ฐ„ ๋…ธ์ถœ๋˜์–ด ๊ณ„์ธก์„ ์ˆ˜ํ–‰ํ•ด์•ผ ํ•˜๋ฏ€๋กœ IoT ์„ผ์„œ์˜ ์ผ€์ด์Šค๋Š” ์•Œ๋ฃจ๋ฏธ๋Š„ ์žฌ์งˆ๋กœ ์ œ์ž‘ํ•˜์˜€์œผ๋ฉฐ, ํ•ด์ƒ ๋„๋กœ ์ƒ ์—ผ๋ถ„, ๋ถ„์ง„, ์ˆ˜๋ถ„ ๋“ฑ์— ์˜ํ•œ ์˜ค์ž‘๋™์„ ์ค„์ด๊ธฐ ์œ„ํ•˜์—ฌ ์™ธ์žฅ ํฌํŠธ๋Š” IP65 ๋“ฑ๊ธ‰ ๊ธฐ์ค€์œผ๋กœ ์ œ์ž‘ํ•˜์˜€๋‹ค.

4. ๊ต๋Ÿ‰ ์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง ์ž๋™ํ™” ์‹œ์Šคํ…œ์˜ ํ˜„์žฅ ์ ์šฉ

4.1 IoT ์„ผ์„œ ์„ค์น˜

๊ฐœ๋ฐœ๋œ ์„ผ์„œ์˜ ํ˜„์žฅ ์ ์šฉ ๋ฐ ๊ฒ€์ฆ์„ ์œ„ํ•˜์—ฌ, ํ˜„์žฌ ์œ ์„  ๊ณ„์ธก์‹œ์Šคํ…œ์„ ํ†ตํ•˜์—ฌ ์ผ€์ด๋ธ” ์žฅ๋ ฅ์„ ๊ด€๋ฆฌ ์ค‘์ธ ๊ตญ๋‚ด ์‚ฌ์žฅ๊ต 1๊ฐœ์†Œ๋ฅผ ์„ ์ •ํ•˜์˜€๋‹ค. ๋Œ€์ƒ ๊ต๋Ÿ‰์€ ์ฃผ๊ฒฝ๊ฐ„ 430 m์˜ ์™•๋ณต 4์ฐจ์„  ๊ฐ•ํ•ฉ์„ฑ ์‚ฌ์žฅ๊ต์ด๋‹ค. ์„ผ์„œ๋ฅผ ์„ค์น˜ํ•œ 2023๋…„ 10์›” 18์ผ๋ถ€ํ„ฐ ํ˜„์žฌ๊นŒ์ง€ ๋ชจ๋‹ˆํ„ฐ๋ง์„ ์ˆ˜ํ–‰ํ•˜๊ณ  ์žˆ์œผ๋ฉฐ, ๊ธฐ์กด ๊ณ„์ธก์‹œ์Šคํ…œ์—์„œ ์ถ”์ถœ๋œ ์ผ€์ด๋ธ” ์ง„๋™ ์‹ ํ˜ธ์˜ ์ฒจ๋‘๊ฐ’๊ณผ ๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ์— ํƒ‘์žฌ๋œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ํ†ตํ•ด ๊ณ„์‚ฐ๋œ ์ฒจ๋‘๊ฐ’์„ ๋น„๊ตํ•จ์œผ๋กœ์จ ๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ์˜ ์ •ํ™•๋„ ๋ฐ ํ˜„์žฅ ์ ์šฉ์„ฑ์„ ๊ฒ€์ฆํ•˜์˜€๋‹ค.

๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ๋Š” ๊ต๋Ÿ‰์˜ ๋™์ธก ์ฃผํƒ‘์— ์„ค์น˜๋œ ์ผ€์ด๋ธ” ์ค‘ ์ค‘์•™๊ฒฝ๊ฐ„ ๋ฐ ์ธก๊ฒฝ๊ฐ„ ๋ฐฉํ–ฅ์œผ๋กœ ๊ฐ€์žฅ ๊ธด ์ผ€์ด๋ธ”์— ๊ฐ๊ฐ 1๊ฐœ์”ฉ ์„ค์น˜ํ•˜์˜€๋‹ค. ์ค‘์•™๊ฒฝ๊ฐ„ ๋ฐฉํ–ฅ์˜ ์ผ€์ด๋ธ” ๋ผ๋ฒจ์€ CSNE17, ์ธก๊ฒฝ๊ฐ„ ๋ฐฉํ–ฅ์˜ ์ผ€์ด๋ธ” ๋ผ๋ฒจ์€ CNNE17์ด๋‹ค. ์„ค์น˜๋œ ์ผ€์ด๋ธ”์˜ ์ œ์›์€ Table 2์™€ ๊ฐ™๋‹ค. CSNE17 ์ผ€์ด๋ธ”์— ์žฅ์ฐฉ๋œ ๊ธฐ์กด ๊ณ„์ธก์„ผ์„œ ๋ผ๋ฒจ์€ CSNE17, CNNE17 ์ผ€์ด๋ธ”์— ์žฅ์ฐฉ๋œ ๊ณ„์ธก์„ผ์„œ ๋ผ๋ฒจ์€ CNNE17์ด๋‹ค.

Table 2 Cable specifications for measurements

Label

CNNE17

CSNE17

Weight per Length (kN/m)

0.5975

0.8414

Effective Length (m)

235.858

198,942

Design Tension (kN)

4,353

6,218

Tension Measurement (kN, 2019)

4,756

6,890

Allowable tension (kN)

5,399

7,659

Fig. 6์€ IoT ์„ผ์„œ์˜ ์„ค์น˜ ์ „๊ฒฝ์„ ๋ณด์—ฌ์ค€๋‹ค. IoT ์„ผ์„œ๋Š” ํ˜„์žฌ ์„ค์น˜๋œ ์œ ์„  ๊ฐ€์†๋„๊ณ„ ์ธ๊ทผ์— ์„ค์น˜ํ•˜์˜€์œผ๋ฉฐ, 3์ถ• ๊ฐ€์†๋„ ๋ฐ์ดํ„ฐ๋ฅผ 100 Hz๋กœ 24์‹œ๊ฐ„ ๊ณ„์ธกํ•œ๋‹ค. ๊ณ„์ธก๋œ ๋ฐ์ดํ„ฐ๋Š” ์›ํ™œํ•œ ๋ฐ์ดํ„ฐ ์ „์†ก์„ ์œ„ํ•˜์—ฌ 10๋ถ„ ๋‹จ์œ„๋กœ ์ €์žฅ, ๋ถ„์„, ์ „์†กํ•˜๋„๋ก ์„ค์ •ํ•˜์˜€๋‹ค. ๋ฐ์ดํ„ฐ๋Š” LTE ํ†ต์‹ ๋ง์„ ์‚ฌ์šฉํ•˜์—ฌ ์†ก์ˆ˜์‹ ๋œ๋‹ค. ์„ฑ๋Šฅ ๊ฒ€์ฆ์ด ์ฃผ์š” ๋ชฉ์ ์ด๊ธฐ์— ์ž์ฒด ๊ณ„์‚ฐ๋œ ์žฅ๋ ฅ ๊ฐ’ ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ๊ฐ€์†๋„ ์›์‹œ ๋ฐ์ดํ„ฐ, ํƒ์ง€๋œ ์ฒจ๋‘๊ฐ’๋„ ํ•จ๊ป˜ ์ „์†กํ•˜๋„๋ก ํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ ์•ˆ์ •์ ์ธ ์ „๋ ฅ๊ณต๊ธ‰์„ ์œ„ํ•˜์—ฌ ํƒœ์–‘๊ด‘ ํŒจ๋„์„ ํ•จ๊ป˜ ์„ค์น˜ํ•˜์˜€์œผ๋ฉฐ, ํƒœ์–‘๊ด‘ ํŒจ๋„์„ ํ†ตํ•œ ์ถฉ์ „ ์ „๋ ฅ๋Ÿ‰์ด ์ถฉ๋ถ„ํ•˜์ง€ ์•Š๊ฑฐ๋‚˜ ๋ฐฐํ„ฐ๋ฆฌ ์ž์ฒด์— ๋ฌธ์ œ๊ฐ€ ๋ฐœ์ƒํ•  ๊ฒฝ์šฐ๋ฅผ ๋Œ€๋น„ํ•˜์—ฌ ์„ผ์„œ ๋‚ด๋ถ€์— ๋ณด์กฐ ๋ฐฐํ„ฐ๋ฆฌ๋ฅผ ํƒ‘์žฌํ•˜์˜€๋‹ค. ๋ณด์กฐ ๋ฐฐํ„ฐ๋ฆฌ๋Š” ์ตœ๋Œ€ 2์ผ๋™์•ˆ ์™ธ๋ถ€ ์ „์› ๊ณต๊ธ‰ ์—†์ด ๋™์ž‘ํ•  ์ˆ˜ ์žˆ๋„๋ก ์„ค๊ณ„ํ•˜์˜€๋‹ค.

Fig. 6 Field installation for verification of developed IoT sensors
../../Resources/ksm/jksmi.2024.28.3.66/fig6.png

4.2 ์ผ€์ด๋ธ” ์žฅ๋ ฅ ์ถ”์ • ์•Œ๊ณ ๋ฆฌ์ฆ˜ ๊ฒ€์ฆ

๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ์˜ ์›์‹œ ๋ฐ์ดํ„ฐ ์ธก์ • ์ •ํ™•๋„๋ฅผ ๊ฒ€์ฆํ•˜๊ธฐ ์œ„ํ•˜์—ฌ, ์„ค์น˜ ์งํ›„ ๊ธฐ์กด ์œ ์„  ๊ณ„์ธก์‹œ์Šคํ…œ ๋ฐ IoT ์„ผ์„œ์—์„œ ์ˆ˜์ง‘๋œ ๊ฐ€์†๋„ ์›์‹œ ๋ฐ์ดํ„ฐ๋ฅผ ์ฃผํŒŒ์ˆ˜ ์˜์—ญ์œผ๋กœ ๋ณ€ํ™˜ํ•œ ๊ฒฐ๊ณผ๋ฅผ Fig. 7์— ๋น„๊ตํ•˜์˜€๋‹ค. ์ฃผํŒŒ์ˆ˜ ์˜์—ญ์—์„œ ๋‘ ์‹ ํ˜ธ์˜ ์ƒ๊ด€๊ณ„์ˆ˜๋Š” 0.957์ด์—ˆ์œผ๋ฉฐ, ๊ฐ ๊ณ„์ธก์‹œ์Šคํ…œ์œผ๋กœ๋ถ€ํ„ฐ ์ถ”์ •๋œ ์žฅ๋ ฅ๊ฐ’์€, ์œ ์„  ๊ณ„์ธก์‹œ์Šคํ…œ์€ 4,756 kN, IoT ๊ณ„์ธก์‹œ์Šคํ…œ์€ 4,574 kN์ด์—ˆ๋‹ค. ์œ ์„  ๊ณ„์ธก ์‹œ์Šคํ…œ์„ ๊ธฐ์ค€์œผ๋กœ IoT ๊ณ„์ธก ์‹œ์Šคํ…œ์˜ ์˜ค์ฐจ๋Š” ์•ฝ 3.8% ์ˆ˜์ค€์œผ๋กœ ๋งค์šฐ ์ž‘์•˜๋‹ค. ์ด๋กœ๋ถ€ํ„ฐ ๋ณธ ๋…ผ๋ฌธ์—์„œ ๊ฐœ๋ฐœ๋œ IoT ๊ณ„์ธก ์‹œ์Šคํ…œ์ด ์ •ํ™•ํ•˜๊ฒŒ ๋Œ€์ƒ ์ผ€์ด๋ธ”์˜ ์ง„๋™์„ ๋ชจ๋‹ˆํ„ฐ๋งํ•˜๊ณ  ์žˆ์Œ์„ ํ™•์ธํ•˜์˜€๋‹ค.

๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ๋กœ๋ถ€ํ„ฐ ์•ฝ 6๊ฐœ์›”๊ฐ„ ๋ชจ๋‹ˆํ„ฐ๋งํ•œ ์ง„๋™ ๋ฐ์ดํ„ฐ๋ฅผ Fig. 8(a)์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. Fig. 8(b)๋Š” ํƒœ์–‘๊ด‘ ํŒจ๋„๋กœ๋ถ€ํ„ฐ ์ถฉ์ „๋˜๋Š” ์ถ•์ „์ง€ ์ „์•• ๋ฐ์ดํ„ฐ๋กœ, ๊ธฐ์ƒ์ฒญ์—์„œ ์ œ๊ณตํ•˜๋Š” ์ผ์กฐ์œจ ๋ฐ์ดํ„ฐ์™€ ํ•จ๊ป˜ ๋„์‹œํ•˜์˜€๋‹ค. ์ถ•์ „์ง€ ์ „์••์€ ๋ชจ๋‹ˆํ„ฐ๋ง ๊ธฐ๊ฐ„ ์ค‘ 12~15V๋ฅผ ์œ ์ง€ํ•˜์˜€์œผ๋‚˜, 2์›” ๋ง ์ผ์กฐ์ผ์ด ๋‚ฎ์€ ๊ธฐ๊ฐ„์ด ์ง€์†๋˜๋ฉด์„œ 0์œผ๋กœ ํ•˜๊ฐ•ํ•˜์˜€๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ฆ‰์‹œ ๋‚ด๋ถ€ ๋ฐฐํ„ฐ๋ฆฌ ์ž‘๋™ ๋ชจ๋“œ๋กœ ๋ณ€ํ™˜๋˜๋ฉด์„œ Fig. 8(a)์™€ ๊ฐ™์ด ๋ฐ์ดํ„ฐ ์†์‹ค ์—†์ด ๊ณ„์ธก์„ ์ˆ˜ํ–‰ํ•˜์˜€์Œ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค.

Fig. 7 Comparison of peak frequencies for wired and IoT systems
../../Resources/ksm/jksmi.2024.28.3.66/fig7.png
Fig. 8 Measured raw data during 6 months
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2023๋…„ 10์›” 20์ผ๋ถ€ํ„ฐ 2024๋…„ 3์›” 25์ผ๊นŒ์ง€์˜ Z์ถ• ์ง„๋™ ๋ฐ์ดํ„ฐ๋กœ๋ถ€ํ„ฐ ํƒ์ง€๋œ ์ฒจ๋‘ ๊ฒฐ๊ณผ๋ฅผ Fig. 9์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. ๊ทธ๋ฆผ์—์„œ ๋ฐ์ดํ„ฐ ๊ฒฐ์ธก๊ตฌ๊ฐ„์€ ํ”„๋กœ๊ทธ๋žจ์ด ์ˆ˜์ •๋œ ๊ธฐ๊ฐ„์— ํ•ด๋‹นํ•œ๋‹ค. 0~20 Hz ๊ตฌ๊ฐ„์—์„œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ํ†ตํ•ด ์ž๋™์œผ๋กœ ์ถ”์ถœ ๋ฐ ๊ณ„์‚ฐ๋œ ์ฒจ๋‘๊ฐ’์€ ๊ณ„์ธก๊ธฐ๊ฐ„ ๋™์•ˆ ์ผ์ •ํ•˜์˜€์œผ๋ฉฐ, ์ฒจ๋‘ ํƒ์ง€์— ๊ฒฐ์ธก์ด ๋ฐœ์ƒํ•˜์ง€ ์•Š์•˜๋‹ค. ์ด๋กœ๋ถ€ํ„ฐ ์„ผ์„œ์˜ ์ง„๋™ ๊ณ„์ธก ์„ฑ๋Šฅ ๋ฐ ํƒ‘์žฌ๋œ ์ฒจ๋‘ ํƒ์ง€ ์ž๋™ํ™” ์•Œ๊ณ ๋ฆฌ์ฆ˜์˜ ์„ฑ๋Šฅ ๋ชจ๋‘ ์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง ๊ธฐ๊ฐ„ ์ค‘ ์ด์ƒ์ด ์—†์Œ์„ ์•Œ ์ˆ˜ ์žˆ์—ˆ๋‹ค.

Fig. 9 Peak detection performance of the proposed IoT sensor
../../Resources/ksm/jksmi.2024.28.3.66/fig9.png

์„ผ์„œ์—์„œ ์ž๋™์œผ๋กœ ์ถ”์ถœ๋œ ์ฒจ๋‘๊ฐ’์œผ๋กœ๋ถ€ํ„ฐ ์ถ”์ •๋œ ์ผ€์ด๋ธ” ์›” ํ‰๊ท  ์žฅ๋ ฅ๊ฐ’์„ Fig. 10์— ๋‚˜ํƒ€๋‚ด์—ˆ์œผ๋ฉฐ, 2023๋…„ ์ธ์œ„์ ์ธ ์ง„๋™์„ ์ธ๊ฐ€ํ•˜์—ฌ(forced vibration) ์œ ์„  ๊ฐ€์†๋„ ๊ณ„์ธก์‹œ์Šคํ…œ์œผ๋กœ๋ถ€ํ„ฐ ์ธก์ •ํ•œ ์žฅ๋ ฅ๊ฐ’๊ณผ ๋น„๊ตํ•˜์˜€๋‹ค. ๋‹น์‹œ CNNE17 ์ผ€์ด๋ธ”์˜ ์žฅ๋ ฅ๊ฐ’์€ 6,907.9 kN, CSNE17 ์ผ€์ด๋ธ”์˜ ์žฅ๋ ฅ๊ฐ’์€ 4,733.2 kN์ด์—ˆ์œผ๋ฉฐ, Fig. 10์—์„œ ๋นจ๊ฐ„์ƒ‰ ์ ์„ ์œผ๋กœ ํ‘œ์‹œํ•˜์˜€๋‹ค. ๋ชจ๋‹ˆํ„ฐ๋ง ๊ธฐ๊ฐ„ ๋™์•ˆ ๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ๋กœ๋ถ€ํ„ฐ ์ถ”์ •๋œ ์žฅ๋ ฅ๊ฐ’์˜ ํ‰๊ท ์€ ๊ฐ๊ฐ 6,891.6 kN, 4,691.1 kN์ด์—ˆ์œผ๋ฉฐ, 2023๋…„ ์ธก์ •๊ฐ’๊ณผ์˜ ์˜ค์ฐจ๋Š” ๊ฐ๊ฐ 0.77 %, 0.23 %๋กœ ํ‰๊ท  0.5%์˜€๋‹ค.

ํ–ฅํ›„ ๊ธฐ์กด์˜ ์œ ์„  ๊ณ„์ธก์‹œ์Šคํ…œ์œผ๋กœ ๋ชจ๋‹ˆํ„ฐ๋ง๋œ ์ง„๋™ ๋ฐ์ดํ„ฐ์™€ ๊ฐœ๋ฐœ๋œ IoT ๊ณ„์ธก์‹œ์Šคํ…œ์˜ ๋ชจ๋‹ˆํ„ฐ๋ง ๋ฐ์ดํ„ฐ๋กœ๋ถ€ํ„ฐ ๊ฐ๊ฐ ๊ณ„์‚ฐ๋œ ์žฅ๋ ฅ ๋ฐ ๊ฐ์‡ ๋น„๋ฅผ ๋น„๊ตยท๋ถ„์„ํ•˜์—ฌ, ๊ฐœ๋ฐœ๋œ IoT ๊ณ„์ธก์‹œ์Šคํ…œ์„ ํ™œ์šฉํ•œ ์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง์˜ ์•ˆ์ •์„ฑ, ์„ผ์„œ ํƒ‘์žฌ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ํ†ตํ•œ ๊ณ ๋„ ์—ฐ์‚ฐ ์„ฑ๋Šฅ ๋“ฑ์„ ๊ฒ€์ฆํ•จ์œผ๋กœ์จ, IoT ์„ผ์„œ๋ฅผ ํ™œ์šฉํ•œ ์ผ€์ด๋ธ” ์•ˆ์ „์„ฑ ๋ชจ๋‹ˆํ„ฐ๋ง์˜ ์™„์ „ ์ž์œจํ™”๊ฐ€ ๊ฐ€๋Šฅํ•  ๊ฒƒ์œผ๋กœ ๊ธฐ๋Œ€ํ•œ๋‹ค.

Fig. 10 Estimation of cable tension from the proposed IoT sensor
../../Resources/ksm/jksmi.2024.28.3.66/fig10.png

5. ๊ฒฐ ๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์‚ฌ์žฅ๊ต์˜ ์ฃผ์š” ๊ตฌ์กฐ๋ถ€์žฌ์ธ ์ผ€์ด๋ธ”์„ ์ธ๋ ฅ์˜ ๊ฐœ์ž… ์—†์ด ์ž์œจ์ ์œผ๋กœ ๋ชจ๋‹ˆํ„ฐ๋งํ•  ์ˆ˜ ์žˆ๋„๋ก Edge Computing์ด ๊ฐ€๋Šฅํ•œ IoT ๊ธฐ๋ฐ˜ ๊ณ„์ธก ์‹œ์Šคํ…œ์„ ๊ฐœ๋ฐœํ•˜์˜€๋‹ค. ์ผ€์ด๋ธ” ๊ต๋Ÿ‰์„ ์žฅ๊ธฐ๊ฐ„ ํšจ์œจ์ ์œผ๋กœ ๋ชจ๋‹ˆํ„ฐ๋งํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ์ •ํ™•๋„๊ฐ€ ๋†’์œผ๋ฉด์„œ ์ž๋™ํ™”๊ฐ€ ๊ฐ€๋Šฅํ•œ ์ฒจ๋‘๊ฐ’ ์ถ”์ถœ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ํƒ‘์žฌํ•˜์—ฌ ์šด์˜ํ•  ์ˆ˜ ์žˆ๋„๋ก, ์š”๊ตฌ ์„ฑ๋Šฅ์— ๋งž๋Š” IoT ์„ผ์„œ๋ฅผ ์ œ์ž‘ํ•˜๊ณ  ์ด๋ฅผ ํ˜„์žฅ์— ์„ค์น˜ํ•˜์—ฌ ๊ฒ€์ฆํ•˜์˜€๋‹ค. ๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ๋Š” ์ผ€์ด๋ธ” ์žฅ๋ ฅ์„ ์ถ”์ •ํ•˜๊ธฐ ์œ„ํ•œ ๋ฐฉ๋ฒ•์œผ๋กœ ์ง„๋™๋ฒ•์„ ์‚ฌ์šฉํ•˜์˜€์œผ๋ฉฐ, ๊ธฐ์กด ์ธ๋ ฅ ์ค‘์‹ฌ์˜ ์ฒจ๋‘ ํƒ์ง€ ๋ฐฉ๋ฒ•์—์„œ ๋ฒ—์–ด๋‚˜ ๊ณ„์ธก๋œ ๊ฐ€์†๋„ ๋ฐ์ดํ„ฐ์—์„œ ์ž๋™์œผ๋กœ ์ฒจ๋‘๊ฐ’์„ ์ถ”์ถœํ•  ์ˆ˜ ์žˆ๋Š” ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ํƒ‘์žฌํ•˜์˜€๋‹ค. ๊ตญ๋‚ด์— ์œ„์น˜ํ•œ ์‚ฌ์žฅ๊ต์˜ ์ผ€์ด๋ธ” 2๊ฐœ์†Œ์— ๋Œ€ํ•˜์—ฌ ๊ฐœ๋ฐœ๋œ IoT ์„ผ์„œ๋ฅผ ์„ค์น˜ํ•˜์˜€์œผ๋ฉฐ, 2023๋…„ 10์›”๋ถ€ํ„ฐ ๋ชจ๋‹ˆํ„ฐ๋ง์„ ์ˆ˜ํ–‰ ์ค‘์ด๋‹ค. ์•ฝ 6๊ฐœ์›”๊ฐ„ ์•ˆ์ •์ ์ธ ๋ฐ์ดํ„ฐ๋ฅผ 100 Hz ์ƒ˜ํ”Œ๋ง์œผ๋กœ ๊ณ„์ธกํ•จ์„ ํ™•์ธํ•˜์˜€์œผ๋ฉฐ, ์ˆ˜์‹ ์œจ ๋“ฑ์„ ํ†ตํ•ด ์•ˆ์ •์ ์œผ๋กœ ์šด์˜๋จ์„ ํ™•์ธํ•˜์˜€๋‹ค. ํƒ‘์žฌ๋œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์œผ๋กœ๋ถ€ํ„ฐ ์ž๋™์œผ๋กœ ํƒ์ง€๋œ ์ฒจ๋‘๊ฐ’์œผ๋กœ๋ถ€ํ„ฐ ๊ณ„์‚ฐ๋œ ์ผ€์ด๋ธ” ์žฅ๋ ฅ๊ฐ’๊ณผ ๊ธฐ์กด์— ๊ณ„์ธก๋œ ์ผ€์ด๋ธ” ์žฅ๋ ฅ๊ฐ’๊ณผ ๋น„๊ตํ•œ ๊ฒฐ๊ณผ ์žฅ๋ ฅ ์ถ”์ • ์˜ค์ฐจ๋Š” ํ‰๊ท  0.5%์˜€๋‹ค. ์ง€์†์ ์ธ ๋ชจ๋‹ˆํ„ฐ๋ง์„ ํ†ตํ•˜์—ฌ ์„ผ์„œ์˜ ๋‚ด๊ตฌ์„ฑ, ๊ณ„์ธก์˜ ๊ฐ•๊ฑด์„ฑ, ๊ด€๋ฆฌ ํšจ์œจ์„ฑ ๋“ฑ์„ ๊ฒ€์ฆํ•  ๊ณ„ํš์ด๋‹ค.

๊ฐ์‚ฌ์˜ ๊ธ€

๋ณธ ์—ฐ๊ตฌ๋Š” ๊ณผํ•™๊ธฐ์ˆ ์ •๋ณดํ†ต์‹ ๋ถ€ ํ•œ๊ตญ๊ฑด์„ค๊ธฐ์ˆ ์—ฐ๊ตฌ์› ์—ฐ๊ตฌ์šด์˜๋น„์ง€์›(์ฃผ์š”)์‚ฌ์—…์œผ๋กœ ์ˆ˜ํ–‰๋˜์—ˆ์Šต๋‹ˆ๋‹ค(Edge computing์„ ํ™œ์šฉํ•œ ๋„๋ฉ”์ธ ์ง€์‹ ๊ธฐ๋ฐ˜ ์ž์œจ ์ผ€์ด๋ธ” ๋ชจ๋‹ˆํ„ฐ๋ง ์‹œ์Šคํ…œ ๊ตฌํ˜„ ์—ฐ๊ตฌ, No. 20240159-001).

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